Quite simply the RCS 140 on a 12 pound sport plane is very nice but is not a viable engine for a pattern bird at that weight. A freind of mine installed his RCS 140 on a 90 Funtana, and after trying more than a few props took it off and reinstalled his glow motor. The engine makes average power. With some work it could be made to put out very good power, but is really not worth the effort. At best its a overpriced sport engine.